1. Field of the Invention
This invention relates to hinges for pivotally connecting the back frame of a vehicle seat and the cushion panel of a vehicle seat and, more particularly, to a releaseable locking device capable of being externally controlled for adjusting the angle of inclination of the back cushion relative to the seat cushion.
2. Description of the Prior Art
It is well known for the back frame of a vehicle seat to be adjustable in position relative to the cushion frame according to the requirements of the occupant. Although various types of hinge arrangements are known to permit such adjustment, a continuing need exists to provide such a hinge which is relatively inexpensive and capable of being reliably utilized throughout the life of the automobile.
As generally disclosed in U.S. Pat. Nos. 3,309,139; 3,788,698; 3,848,923; 3,897,608; 3,900,225; 3,902,757 and 3,931,996, there have been utilized seat hinges with lever actuated engaging means for selecting the relative angle of the hinge arms and for maintaining that angle according to the desires of the user. These devices typically include an extended lever arm which acts upon a pivotally mounted engaging element which is located remotely from the hinge axis.
There are, however, other devices such as those disclosed in U.S. Pat. No. 3,737,946 utilizing a different configuration which generally includes an arcuate rack associated with one arm of the hinge and a selectively engageable and disengageable pawl associated with the other arm of the hinge for selecting and maintaining the angle between the arms as desired. This device includes operating elements which are better protected and more compactly arranged than those discussed above. However, the means provided in this prior art device utilize camming surfaces to operate on a portion of the pawl in an unsupported, cantilevered fashion. Such an arrangement over the extended life of an automobile could result in bending or breaking of that portion of the pawl which is the primary area where forces are generated to produce this movement.